| Pachystachys lutea Nees, 1847 |
| Pachystachys spicata (Ruiz & Pav.) Wassh., 1986 |
| Petalidiinae Benth. & Hook. f., 1876 |
| Poikilacanthus Lindau, 1895 |
| Poikilacanthus capitatus (Leonard) Ramamoorthy, 1989 |
| Poikilacanthus foliosepalus T.F. Daniel, 2017 |
| Poikilacanthus macranthus Lindau, 1895 |
| Poikilacanthus novogalicianus T.F. Daniel, 1991 |
| Poikilacanthus pochutlensis T.F. Daniel, 2017 |
| Poikilacanthus setifer Standl. & Steyerm., 1947 |
| Poikilacanthus skutchii D.N. Gibson, 1972 |
| Psacadocalymma Bremek., 1948 |
| Psacadocalymma comatum (L.) Bremek., 1948 |
| Psacadocalymma pectorale (Jacq.) Bremek., 1948 |
| Pseuderanthemum Radlk., 1883 |
| Pseuderanthemum alatum (Nees) Radlk., 1883 |
| Pseuderanthemum atropurpureum (W. Bull) Radlk., 1883 |
| Pseuderanthemum carruthersii (Seem.) Guillaumin, 1948 |
| Pseuderanthemum cuspidatum (Nees) Radlk., 1883 |
| Pseuderanthemum fasciculatum (Oerst.) Leonard, 1938 |